This invention relates to the use of forward diffracted light to measure the volume loading of a collection of particles suspended in a fluid sample. It is particularly applicable where, in the range being measured, the suspended particles are in such concentration that the forward diffracted light varies nonlinearly with changes in the volume loading. More particularly, this invention relates to the linearization of the relationship between the volume loading in the sample and the detected forward scattered light which is measured as a function of the volume loading. The volume loading is the total volume of the suspended particles per unit of sample. It has been found that as the total volume of the particles in a unit volume of sample increases beyond an initial low concentration the amount of scattered light detected does not vary in a substantially linear relationship with the changes in total particle volume. Instead the total particle volume varies in a nonlinear fashion with the change in the detected signal falling off as the concentration of particle volume increases.
It is an object of this invention to provide a method and means for linearizing the measurement of the volume loading as the volume loading of the sample varies over a wide dynamic range.